A Janet Jackson album (since Control, natch) is always a Janet Jackson album, if you know what I mean: her personality is so distinctive as to render comparisons irrelevant. Which makes it all the more jarring to hear Miss Jackson singing interchangeable tracks on her new 20 Y.O.. “Show Me,” for instance, could just as easily be a Ciara single (though perhaps not Rihanna; distinctions are cost-effective in this case), and “Get It Out Me” could damned near be a second-tier R&B girl group (Cherish, perhaps?). The blame for this goes largely to Dupri, Jackson’s boyfriend and co-producer on much of 20 Y.O. (alongside her original collaborators/inventors, Jimmy “Jam” Harris and Terry Lewis), who plugs Janet into one electro-funk cut after another.

Not all is lost. “Do It 2 Me” succeeds in spite of Dupri’s “bounce with me” exhortations—c’mon, JD, this ain’t a record by Da Brat, or even Mariah for that matter—largely thanks to its sample from Brenda Russell’s “If Only for One Nite.” “Call on Me,” in the ultimate in meta-sampling, “contains elements” from the S.O.S. Band’s “Tell Me If You Still Care,” written by Harris & Lewis over two decades ago. It’s a lovely little pillow of a midtempo ballad, with Janet singing off Nelly (who’s also singing, which he arguably does better than he raps).

There are glimmers of the “old” Janet (as opposed to the 40-year-old Janet) on tracks such as “Daybreak,” a less buoyant “Escapade” remake and the breezy “Enjoy,” which could be an outtake from The Velvet Rope. (Both, unsurprisingly, are Dupri-free.) And the sexed-up “So Excited” rides a Herbie Hancock groove and a throwaway contribution from Khia (?!) to, if not ultimate satisfaction, at least a half-decent orgasm.

“Half-decent” is precisely the problem with 20 Y.O.—there’s precious little to get, well, excited about here. Janet commits the ultimate sin of making an album that’s thoroughly mediocre. Apart from the sticky ear-candy of “So Excited,” there’s little I’d miss here if I went six months without it. This doesn’t sound like rejuvenation—it sounds like the beginning of the end.